NV5 20260127 Raster Digital Data Product: Topobathymetric Digital Elevation Model (DEM) data covering the OR John Day Topobathymetric Lidar project area. Geographic Extent: This dataset and derived products encompass an area covering approximately 7,021 acres of Northeast Oregon. Dataset Description: Lidar flight line swaths were processed to create 165 classified LAS 1.4 files delineated in 1,000m x 1,000m tiles. Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. The data was developed based on a horizontal projection/datum of UTM Zone 11 N, NAD83(2011), Meters and vertical datum of NAVD88 Geoid 18, Meters. Class 2 (ground) and class 40 (bathymetric bottom) lidar points were used to create a 165 1.0 meter topobathymetric Raster DEMs delineated in 1,000m x 1,000m tiles. This version of the topobathymetric model has been clipped. Areas of bathymetric voids were triangulated from the nearest bathymetric returns. Users should be aware that bathymetric voids can indicate deeper areas beyond the penetration capabilities of the laser and view these as low confidence areas. Non-Vegetated Vertical Accuracy (NVA) was assessed using 35 check points located on bare earth in clear, unobstructed areas. Vegetated Vertical Accuracy (VVA) was assessed using 35 check points in Tall Grass, Forest, and Shrub landcover types. Additional products include classified LAS files, intensity images, maximum surface height rasters, and a bathymetric void shape. Ground Conditions: Ground condition was free of snow and acquisition occurred free of smoke, fog and cloud cover. The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3D Elevation Program and the OR John Day Topobathymetric Lidar contract. The lidar point cloud data were used to create classified LAS files, intensity images, topobathymetric DEMs, maximum surface height rasters, and a bathymetric void shape. Raster File Type = TIFF Bit Depth/Pixel Type = 32-bit float Raster Cell Size = 1.0 meter Interpolation or Resampling Technique = Triangulated Irregular Network 20250826 20251028 ground condition Complete None planned -119.419675 -118.427517 44.938161 44.565022 309032.316898 386673.892366 4977084.380852 4937470.124539 none model Raster DEM Bare Earth Bathymetry Topobathy remote sensing Elevation data Lidar Umatilla National Forest, Monument Oregon No restrictions apply to these data. None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data. DEM files were tested by NV5 for vertical accuracy. A visual qualitative assessment was performed to ensure data completeness. A bathymetric void shape has been provided as a separate deliverable. The classified point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications. This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (Edition 2) for a 0 (cm) RMSEx / RMSEy Horizontal Accuracy Class which equates to the Positional Horizontal Accuracy = +/- 0 cm at RMSEh. 0 Lidar horizontal accuracy is a function of Global navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. Using a flying altitudes of 300 meters, an IMU error of 0.003 decimal degrees, and a GNSS positional error of 0.023 meters, this project was compiled to meet 0 meters horizontal accuracy RMSEh. This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (Edition 2) Vertical Accuracy. The specifications requires the Non-vegetated Vertical Accuracy (NVA) be computed from the derived topobathymetric DEMs. The NVA was tested with 35 independent check points located in open terrain and distributed throughout the project as feasible. These check points were not used in the calibration or post processing of the lidar point cloud data. Specifications for this project require that the NVA be 0.10m or better RMSEv. Vegetated Vertical Accuracy (VVA) is also to be computed from the derived topobathymetric DEMs. The VVA was tested with 35 check points in Tall Grass, Forest, and Shrub land cover types. 0 The 35 independent NVA check points were surveyed using real time kinematics. Elevations interpolated from the derived topobathymetric DEMs were compared to the elevation values of the surveyed NVA check points. The RMSEv was computed to be 0.041 meters. 0 The 35 VVA check points were surveyed using real time kinematics. Elevations interpolated from the derived topobathymetric DEMs surface were compared to the elevation values of the surveyed VVA check points. The RMSEv was computed to be 0.111 meters. Lidar Pre-Processing: 1. Review flight lines and data to ensure complete coverage of the study area and positional accuracy of the laser points. 2. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. 3. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with sensor head position and attitude recorded throughout the survey. 4. Calculate laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Create raw laser point cloud data for the entire survey in *.las format. Convert data to orthometric elevations by applying a Geoid 18 correction. 5. Apply refraction correct to bathymetric returns by flightline. 6. Import raw laser points into manageable blocks to perform manual relative accuracy calibration and filter erroneous points. Classify ground points for individual flight lines. 7. Using ground classified points per each flight line, test the relative accuracy. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calculate calibrations on ground classified points from paired flight lines and apply results to all points in a flight line. Use every flight line for relative accuracy calibration. 8. Adjust the point cloud by comparing ground classified points to supplemental ground control points. OR John Day Topobathymetric Lidar Ground Control 20260127 Lidar Post-Processing: 1. Classify data to ground and other client designated classifications using proprietary classification algorithms. 2. Manually QC data classification 3. Calculate final NVA and VVA vertical accuracy statistics and calculate native and ground density information. 20260127 Breaklines: Water boundary polygons were developed using an algorithm which weights lidar-derived slopes, intensities, and return densities to detect the water's edge. The water's edge was then manually reviewed and edited as necessary. 20260127 bathymetric void shape: Ground and bathymetric bottom points within and near the water's edge breakline were used to construct a Delaunay triangulation. Triangulation across the water's edge breakline to terrestrial ground points may occur. Insufficiently mapped areas denoted as "Void" were identified as areas composed of triangles with edge length maximums greater than or equal to 4.56 meters. Sufficiently mapped areas denoted as "Covered" were identifed as areas composed of triangles with edge length maximums less than 4.56 meters. The bathymetric void shape is clipped to the water's edge breakline extent and percent area is calculated. This shape was used to clip the final topobathymetric DEMs to avoid interpolation over areas lacking bathymetric returns. 20260127 Raster Pixel 1000 1000 Universal Transverse Mercator 11 0.9996 -117 0 500000 0 row and column 1.0 1.0 Meters North American Datum of 1983 (2011) GRS_1980 6378137.0 298.257222101 North American Vertical Datum of 1988, Geoid 18 0.01 Meters Explicit elevation coordinate included with horizontal coordinates 20260127 20260127 NV5 mailing and physical

1100 NE Circle Blvd., Suite 126

Corvallis OR 97330 USA 541-752-1204 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 None None None Unclassified None None None